<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #container {
  padding-left: 200px;
  padding-right: 150px;
  overflow: auto;
}
#container p {
  float: left;
}
.center {
  width: 100%;
  background-color: lightcoral;
}
.left {
  width: 200px;
  position: relative;
  left: -200px;
  margin-left: -100%;
  background-color: lightcyan;
}
.right {
  width: 150px;
  margin-right: -150px;
  background-color: lightgreen;
}
.clearfix:after {
  content: "";
  display: table;
  clear: both;
}
    </style>
</head>
<body>
    <div id="container" class="clearfix">
        <p class="center">我是中间</p>
        <p class="left">我是左边</p>
        <p class="right">我是右边</p>
    </div>

</body>
</html>